I don't think animals in nature move this way! But here's how I got it to click in my brain: Activate the left side, then the right.
By that I mean pull the hand & kick down at the same time on the left.
Then activate both limbs on the right side. Pull the right hand & kick down on the right leg.
It's whole left side experience / then a whole right side experience.
Of course different strokes work for different folks. It makes sense to think of it as a right-spear with left kick too - that's probably more in-line with TI language because it connects through your core in a balanced way.